Iowans are being warned about a new type of device crooks are using on gas pumps and ATMs to steal identities.

Jim Hegarty, CEO of the Better Business Bureau in Omaha/Council Bluffs, says most people have heard of “skimmers” that are placed on top of the slot where you slide a credit card. New devices are being found, called “shimmers,” that are smaller and much harder to spot.

“Because that stuff always ends up emerging in our market, we just want to give people a heads up on it,” Hegarty says, “and most importantly, have them monitoring their accounts online like every day.” The new shimmers will be difficult to notice for ATM and credit card users, while those who are wary might be able to spot the older-style skimmer.

“Sometimes, these devices that have been used historically by thieves are a little bulky,” Hegarty says. “They can be detected. If you look real closely at an ATM, you can probably tell that it’s on there. The gas pumps are more problematic because they’re installed inside.”

There have not yet been any reports of shimmers being found in Iowa, but Hegarty says to be on guard. “You can pretty much bank on the fact that they’re already being used in our market,” he says. “It’s just a matter of when and where we’ll begin discovering that and some arrests will be made. It’s the world we live in today. You just have to be super-cautious.” Hegarty recommends paying for gas inside the store instead of using the pay-at-the-pump option, and go inside the bank for transactions instead of using an ATM.